Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
tranh nghiem » trac nghiem, trai nghiem, doanh nghiep
trach nhiem » trac nghiem
canh trach » canh tranh, khanh trach, canh tac
thu canh » thuc hanh, thu cong, thu ban
nhiem du » hiem du, nghiem dau, nhiem huu
tu sach » thu sach, su sach, te sach
du hoc » tu hoc, duoc hoc
d hoc » ad hoc, de hoc, y hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu canh trach nhiem du hoc ) or ( tu sach ((tranh nghiem) or (trinh nghien)) d hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu canh trach nhiem du hoc ) OR ( tu sach ((tranh nghiem) OR (trinh nghien)) d hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu canh trach nhiem du hoc ) or ( tu sach ((tranh nghiem) or (trinh nghien)) d hoc ))*.